Autism is a brain developmental disorder that is characterized by deficits in social interaction, behavior, and cognitive and language functions. Both functional and morphometric studies have implied that the brain abnormalities that are observed in autism may be associated with impairment of the white matter pathways connecting different brain regions. It has been suggested that communication between remote brain regions (long-range connectivity) is reduced and communication between neighboring brain regions (short-range connectivity) is increased in the autistic brain. To date, no direct study of the anatomical connectivity in autism has been performed. The goal of this project is to investigate the relation between short and long-range anatomical connectivity in autism and the organization of white matter pathways that connect cortical regions involved in face processing. Diffusion Tensor Imaging (DTI) and white matter tractography (WMT) techniques will be used to segment specific white matter structures and to derive structure-specific measures of anatomical connectivity. A comparative study of the anatomical connectivity in high-functioning autistic patients and comparison healthy subjects will be performed. In addition to DTI we will acquire Functional MRI data during a task involving discrimination of facial expressions. We will explore the relations between behavioral and functional measures and anatomical connectivity measures in regions involved in face processing. The results of this study may reveal connectivity alterations in specific pathways or brain regions and thereby contribute to the understanding of the mechanisms underlying brain dysfunction in autism. The study of the white matter pathways involved in face processing will also contribute to the understanding of the abnormal brain activation patterns that are generally observed in autism during face processing tasks and to the understanding of some of the face processing deficits in autism. Autism is a lifelong disorder that is characterized by considerable behavioral, verbal, and social communication impairments. This study will investigate the integrity of the white matter pathways that connect remote and adjacent functional brain regions involved in the discrimination of facial expressions. Knowledge of the impaired brain connectivity will provide new insights into the mechanisms that underlie brain disfunction in autism. [unreadable] [unreadable] [unreadable]